code: def testMultipleWrites(self):
      file_path = os.path.join(self._base_dir, "temp_file")
      with gfile.GFile(file_path, mode="w") as f:
          f.write("line1\n")
          f.write("line2")
      file_contents = gfile._read_file_to_string(file_path)
      self.assertEqual("line1\nline2", file_contents)
  
imports: import os.path
  from tensorboard import test
  from tensorboard.compat.tensorflow_stub import compat, errors
  from tensorboard.compat.tensorflow_stub.io import gfile
label_desc: Use image node_id 8 for calling the FileIoTest obj's underlying member method code with example usage: obj.testMultipleWrites() without return types